Id #

The Id field shows the internal number of the channel under which it is stored internally. When creating a new element, the field is empty. The number is for display purposes only and is automatically defined by the system.

Interface #

Here you can see which interface the channel belongs to and which type the interface has. This information is for viewing purposes only.

Name #

The name of the channel. The name is displayed in selection lists and may also be visible to the user (e.g. if the channel is displayed in a chart or a notification originates from the channel or refers to it).

Comment #

The comment field is for free use by the integrator/system administrator. It is used exclusively to document the configuration. Information can be entered here, e.g. the purpose of the channel, comments on the connected hardware, room/floor and other special features. The content of this field is irrelevant for X2.

Option: Persistent #

If you set this checkbox, X2 saves the current value of the channel persistently (after a restart, the channel then has the last set value again. If the checkbox is off, the channel has no value after a restart until it is either written to or a value is read from the interface.

Option: Chart #

Check this box to record the value of the channel. Channels whose value is recorded can be displayed in charts as graphs. This is suitable for measured values (temperature, humidity, etc.). The average value is calculated over a period of 5 minutes and saved every 5 minutes. The system automatically recognizes when the channel is used for a chart and records data even if you do not set the checkbox. You must set the checkbox yourself if you want the data to be recorded in charts regardless of the use of the channel.

Option: Autoconfig #

If this checkbox is set, some channel settings are automatically defined/overridden by the interface. The checkbox is not available/changeable for all interface types.

Option: Busmaster #

With this checkbox, X2 itself becomes a device for the KNX address, i.e. it will respond to group read requests to the status address on the KNX bus and if X2 receives a group write to the command address, the new value will be output on the status address. Other KNX devices can communicate with the channel exactly as if X2 were an actuator.

Cyclical writing #

Here you can specify that the last written value of the channel is output again to the connected hardware at specified intervals. The setting can only be changed for certain interfaces.

Writing/Reading #

Defines the access mode for the channel, read, write or both. Depending on the interface, this field may not be changeable.

Unit #

Defines the value unit and thus also the data type of the channel. If the autoconfig checkbox is set, some interfaces can override the unit or lock the setting.

Group addr. Command #

The KNX group address to which a group write is sent when the channel is written to. The channel must also be configured as writable.

Group addr. Status #

The KNX group address from which X2 reads the channel value. At startup, X2 attempts to actively read this group address (group read). The value is then continuously updated when a KNX telegram to this address appears on the KNX bus. The channel must also be configured to readable.

Notes on group addresses #

It is common practice with KNX to completely separate command and status addresses, i.e. a value is written under one address and read/reported under another address. It is advantageous to maintain this separation in X2 as well, i.e. to configure a separate channel in X2 for each status and command address. The main reason for this is that if you configure the channel with both addresses and the Read+Write mode, X2 sees a value change when it writes the value itself (the channel can only ever have one value). If you configure separate channels, this better reflects the status on the KNX bus, e.g. a light in the visualization only switches on when the feedback from the actuator arrives at X2 and not when X2 gives the command to switch on.

Data type #

Select the KNX data type here. Make sure that the data type is correct! If you have activated the Autoconfig option, the unit of the channel is defined according to the data type. We recommend always using Autoconfig for KNX channels, it saves work and avoids errors.
However, you can (or must) deviate from this if you have an actuator that does not adhere to the KNX specification (e.g. a sensor that supplies a pressure value in bar, which KNX does not provide for. You would then set the data type 9.006 but the unit would be bar).